https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63794
--- Comment #2 from howarth at bromo dot med.uc.edu --- Unfortunately, due to the number of modules required cmapf_mod.f90, it is impossible to create a small test case. However this problem can be reproduced by downloading the src_flexwrf_v3.1.tar.bz2 source code and executing... make -f makefile.mom serial